The U.S. government says 600,000 commercial drones could fill the nation's skies within a year.

U.S. Transportation Secretary Anthony Foxx opened the way to widespread remote-controlled drone use Monday as new safety rules took effect. He said the country is "captivated by the limitless possibilities unmanned aircraft offer."

The new rules permit businesses to fly drones weighing up to 25 kilograms in sparsely populated areas up to 122 meters above ground from just before dawn each day to just after sunset. In addition, pilots must keep the drones within eyesight and fly them at a speed of no more than 160 kilometers an hour.

Foxx said the United States is developing other transportation related innovations, including automatic braking systems for trains and autonomous cars and trucks.

"Just as we’re seeing innovative technologies transforming our roads and our ports and our seaways, drones are also blazing an uncharted path that will continue to revolutionize our airspace," he said.

The drone industry said it expects increased use of the aircraft will help create 100,000 jobs and $82 billion in economic activity by 2025.

The U.S. already has granted 76 exemptions to the new rules, mostly to companies that want to operate drones at night.

Some of the commercial drones already are being used to monitor crops, inspect bridges and transmission lines, assist firefighters and police officers, film movies and make wedding videos.